This invention relates to a stage for a microscope. More particularly, the invention relates to a stage for a microscope comprising a stage carrier, an object stage, and an intermediate carrier disposed between the stage carrier and the object stage, in which the intermediate carrier and the object stage are displaceable respectively in first and second directions.
This type of stage carrier may also be displaceable in a third direction in space perpendicular both to the first and second directions, relative to a microscope objective.
In known microscopes a first setting mechanism is provided for movement of the intermediate carrier in the first direction, and a second setting mechanism is provided for movement of the object stage in the second direction. A third setting mechanism can be provided for movement of the object stage in the third direction.
The arrangement is such that upon actuation of the first setting mechanism for moving the intermediate carrier in the first direction the object stage, the intermediate carrier, and the first and second setting mechanisms are all moved in the first direction.
This entrainment of the second setting mechanism with the first setting mechanism is disadvantageous, because as a result of the second setting mechanism being entrained the precise position of this second setting mechanism cannot immediately be determined at any time. The operability of microscopes of such a kind is impaired as a result of this. A further defect of these microscopes consists in the low ergonometry, which is present only in a particular setting of the setting mechanisms, while all other settings of the setting mechanisms leave aspects to be desired with regard to ergonometry.
In the case of the application of such microscopes in the semiconductor industry, the object stages are constantly becoming larger: in order to be able to examine wafers having dimensions of 4.times.4 inches (100 mm.times.100 mm), 6.times.6 inches (150 mm.times.150 mm) and 8.times.8 inches (200 mm.times.200 mm) along their entire surface length, it is necessary to be able to adjust the object stage in the first and second directions by at least 4 inches (100 mm), 6 inches (150 mm) or 8 inches (200 mm). In known microscopes actuation of the first setting mechanism by, for example, 8 inches (200 mm) causes displacement of the second setting mechanism by 8 inches (200 mm). Thus, following displacement of the intermediate carrier and the object stage in the first direction the second setting mechanism must first be located; this can be very difficult when the operator is trying to view the object under examination at the same time as effecting the displacement.
The problem is even more acute when an uncoupling element is provided for uncoupling the two setting mechanisms so that rapid adjustment can be performed. Moreover, with the type of stage described above there is always a position of the object stage in which the hand of the operator can collide with the setting mechanism for the setting of the stage carrier in the third direction.
A second mechanism for the setting of the stage carrier and thus of the object stage in the third direction is described in our West German Patent Application Ser. No. P 35 23 756.2, the contents of which are incorporated herein by reference.